The present disclosure relates to a wireless charging system and a method for controlling the same.
In recent years, a wireless power transfer technology which is a method for conveniently supplying or charging power to various kinds of electronic devices without a connection of an electric wire has been actively researched, and thus an interest in the wireless power transfer technology has been suddenly increased. A field of the wireless power transfer technology tends to be expanded from a method of wirelessly charging a personal terminal to a technology of wirelessly charging a battery for a vehicle.
The field of the wireless power transfer technology largely uses an inductive coupling method, an evanescent wave resonance method, a radio frequency (RF) method, and the like. Among those, the currently most efficient and widely used method is the inductive coupling method.
A principle of the inductive coupling method is the same as a basic principle of a transformer. In the wireless charging system, a primary coil and a secondary coil of the transformer are separated from each other and thus the primary coil is equipped in a charging apparatus (hereinafter, transmitting apparatus) and the secondary coil (hereinafter, receiving apparatus) is equipped in a terminal.
In designing the wireless charging system using the inductive coupling method, a current induction between the coils is closely connected with the entire system efficiency and therefore there is a need to design the wireless charging system in consideration of characteristics and matching of coils of transmitting and receiving ends.
Recently, various consumer demands for the wireless charging technology have mainly focused on multiple charging by which a single wireless charging transmitter may charge a plurality of wireless charging receivers. Therefore, many technologies for realizing the multiple charging have been suggested recently.